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IV00673: MBUF CORRUPTION AND POSSIBLE ABEND APPLIES TO AIX 6100-07

A fix is available

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APAR status

  • Closed as program error.

Error description

  • The easiest symptom to spot is a corrupted mbuf which
    will
    lead to an abend.  Since an unrelated mbuf is corrupted,
    the crash can be almost anywhere.
    
    If net malloc police is enabled and 512 allocations
    promoted to a page, then the stack will look something
    like this:
    
    csa at f0000000302f1600 intpri:3 backt:0 ticks:0 thread
    slot:6198 *****
          dar=f10002000b27d000
        dsisr=0000000042000000
        srval=00007fffffffd080
         dar2=f10002000b27d000
        cause=c000000000000106
                 iar: 000000000000f4a4 ___memmove64 + 0xa4 =>
    
    std   r8,0x18(r3)
                  lr: 00000000004309c8 m_copydata + 0x108
    f0000000302f09e0: 00000000048f99d4 [netinet:tcp_output] +
    0xbf4
    f0000000302f0c90: 00000000048f7870 [netinet:tcp_usrreq] +
    0x1550
    f0000000302f0fd0: 0000000000473424 soo_write + 0x3e4
    f0000000302f10b0: 0000000000473000 soo_rw + 0x40
    f0000000302f1120: 00000000004e5a4c rwuio + 0x12c
    f0000000302f11d0: 00000000004e5e08 rdwr + 0x188
    f0000000302f12a0: 00000000004e51ac kewritev + 0x14c
    f0000000302f1510: 0000000000003850 sc_entry_etrc_point +
    0x4
    
    tcp_output is about to touch the mbuf that would have
    otherwise been corrupted.
    

Local fix

  • This is rarely hit and requires a number of conditions to
    trigger.  One condition is that largesend needs to be on
    but checksum offload needs to be off.  The second
    condition
    is that large packets need to be sent when PSEG is off.
    PSEG is on for all packets taking the normal path going
    out normal IBM adapters.  But third party security
    software
    like /opt/CA/eTrustAccessControl/bin/SEOS_syscall cause
    large packets to be sent down without PSEG set.
    

Problem summary

  • system crash with DSI_PROC
    

Problem conclusion

  • Check for largesend and checksum offload feature
    in conditional statement
    

Temporary fix

Comments

APAR Information

  • APAR number

    IV00673

  • Reported component name

    AIX 610 STD EDI

  • Reported component ID

    5765G6200

  • Reported release

    610

  • Status

    CLOSED PER

  • PE

    NoPE

  • HIPER

    NoHIPER

  • Submitted date

    2011-05-18

  • Closed date

    2011-05-18

  • Last modified date

    2013-04-10

Fix information

  • Fixed component name

    AIX 610 STD EDI

  • Fixed component ID

    5765G6200

Applicable component levels

  • R610 PSY U837954

       UP11/10/15 I 1000

PTF to Fileset Mapping

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Document Information

Modified date:
10 April 2013